Flexible Impeller Pump Automated Drainage

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Solution Overview

Problem

Flexible impeller pumps used in the food and pharmaceutical sectors face challenges in complete drainage without disassembly due to their self-priming design, which traps liquid between the impeller and pump casing.

Innovation Solution

Incorporating a drain hole in the pump cover with a solenoid valve and a Venturi-effect device, along with a groove on the cover to facilitate liquid flow and a helical groove on the shaft to prevent liquid trapping, allowing for automated and complete drainage without disassembling the pump.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the pump uses a variable radius profile working chamber to achieve self-priming properties, then the pump can efficiently transfer thick liquids, but the pump cannot be completely drained without disassembling the cover

Engineering Contradiction:
Improveself-priming capabilityVSAvoiddrainage operation
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The invention divides the working chamber into multiple drainage paths by adding axial slots to the impeller hub and radial slots to the impeller blades. This segmentation allows liquid to be drained through multiple channels simultaneously, enabling complete drainage while maintaining the self-priming variable radius profile.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention introduces an intermediary drainage system consisting of slots in the impeller hub and blades that act as conduits. These slots mediate between the trapped liquid in the working chamber and the external environment, allowing liquid to escape without removing the cover while preserving the self-priming structure.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If the impeller blades remain constantly in contact with the lateral surface of the working chamber, then the pump achieves high self-priming efficiency, but liquid becomes trapped between the impeller and pump casing preventing complete drainage

Engineering Contradiction:
Improveself-priming efficiencyVSAvoidtrapped liquid
Core Design Contradiction:
ProductivityVSLoss of substance

Solution Approach 1:

The impeller is segmented with axial slots in the hub and radial slots in the blades, creating multiple drainage channels that allow trapped liquid to escape while maintaining blade contact with the working chamber lateral surface for self-priming efficiency.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The slots are strategically positioned in specific locations - axial slots in the hub and radial slots in the blades - to create localized drainage pathways. This local modification allows liquid to escape from specific trapped regions without affecting the overall self-priming contact between blades and working chamber.

Inventive Principle:
Principle #3Local quality

3Reliability

If the pump is designed with minimal axial space between the chamber and impeller, then the self-priming capability is enhanced, but the pump cannot be drained without disassembling the cover

Engineering Contradiction:
Improveself-priming capabilityVSAvoiddrainage system
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Instead of increasing axial space, the invention segments the impeller structure with slots that create internal drainage pathways. This allows liquid to be drained through the impeller itself without increasing the axial gap between the impeller and pump casing, maintaining the compact self-priming design.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention adds drainage capability in the radial dimension through slots in the impeller blades and hub, rather than relying on axial space. This dimensional approach allows liquid to escape radially through the impeller structure while maintaining minimal axial clearance for self-priming.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Enables efficient and automated drainage of the pump without manual intervention, ensuring complete liquid removal and maintaining the pump's self-priming properties.

Implementation Method 1

a solenoid valve, advantageously provided with a Venturi-effect device, remotely controllable to allow the pump draining process to be automated

Methodology Applied
Scientific EffectVenturi effect: Venturi Effect

Implementation Method 2

the flexible blades, cooperating with the lateral surface of the working chamber, are alternately subject to bending and stretching, thus causing a suction effect

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP4030058B1Flexible impeller pump
Publication Date: 2023.08.09 BRUNO WOLHFARTH
  • EP4030058B1 patent drawingFigure 1
  • EP4030058B1 patent drawingFigure 2
  • EP4030058B1 patent drawingFigure 3~4

AI summary

A pump (10) is described comprising: a pump casing (12) defining internally a working chamber (14), an impeller (16) accommodated in the working chamber (14), a shaft (18) which is rotatably mounted about an axis of rotation (x) and on which the impeller (16) is mounted so as to be drivingly connected for rotation therewith, and a cover (22) fixed on a front side of the pump casing (12) to close the working chamber (14). The working chamber (14) is delimited radially by a lateral surface (30) having a profile with a variable radius with respect to the axis of rotation (x). The impeller (16) comprises a hub (32) and a plurality of blades (36) which extend radially outwards from the hub (32) and are made of a flexible material so as to be alternately deflected and released when the impeller (16) is driven by the shaft (18) into rotation about said axis of rotation (x). The cover (22) has, in a lower region thereof, a drain hole (48) for allowing the liquid contained inside the working chamber (14) to be discharged. The pump (10) further comprises closing means (50, 52, 54, 56, 58, 60) selectively controllable to close or open the drain hole (48) to prevent or allow, respectively, the flow of the liquid out of the working chamber (14) through the drain hole (48).